1. Field of the Invention
This invention generally relates to the catalytic oxidation of olefins to ketones, and more specifically to the formation of ketones by the vapor phase catalytic oxidation of olefins.
2. Description of the Prior Art
British Pat. No. 1,029,175 to Shell describes a vapor phase olefin oxidation process in which olefins are reacted with O.sub.2 at temperatures of less than 350.degree. C. in the presence of water vapor and a halogen, using a supported Group VIII noble metal catalyst containing either an Fe, Ni, Co or Group I or VII transition metal compound, optionally together with an alkali metal compound or one or more transition metal compounds of Groups III-VI. While propylene oxidation is said to give acetone as the main reaction product, such halide-containing systems have severe disadvantages such as the high corrosivity of these systems.
British Pat. No. 876,024 (1961) forms aldehydes and ketones by contacting the corresponding olefin and oxygen over a catalyst containing a strong acid compound of a transition metal of the fifth to eighth group or first sub-group of the Periodic System, in the presence of steam. Illustrated are catalyst compounds containing anions derived from such strong acids as HCl and HBr.
U.S. Pat. No. 2,662,921 (1953) oxidatively converts olefins into unsaturated ketones (e.g., propylene to acrolein) using a catalyst containing at least one oxide of Te and Re, and in the presence of free O.sub.2. Other patents disclosing catalyst systems for forming unsaturated such aldehydes using Re-containing catalysts are: U.S. Pat. Nos. 3,331,871 and 3,451,946 to C. E. Ziegler, et al. (feed=propylene and O.sub.2 and optionally, water vapor, over catalyst containing CoMoO.sub.4, TeO.sub.2 and a Re compound, to form a mixture of acrolein and acrylic acid); and U.S. Pat. Nos. 3,369,049 and 3,423,331 to J. S. Eden et al. (acrolein or methacrolein prepared from propylene or isobutylene and O.sub.2, with or without water vapor, over a catalyst comprising a mixture of certain Cu, Te and Re compounds).
An early patent (U.S. Pat. No. 2,523,686 to W. F. Engel of Shell) employs catalysts containing (1) an oxide of a metal of Groups II, III, IV or VI of the Periodic Table and (2) a metal or partially reduced oxide of a metal of Group IB, Group VII or Group VIII of the Periodic Table, and prepares saturated open-ended ketones from olefins of at least three carbon atoms per molecule in a vapor phase process in the presence of steam and under defined conditions. The U.S. patent indicates that Mn is preferred over other Group VII metals (Re and Ti) in the patentee's catalysts. The catalysts are prepared by partial reduction of the metal oxide with H.sub.2. Dutch Pat. No. 59,179, also to W. F. Engel, relates to similar catalyst systems. Neither patent contains any working example to a Re catalyst system.
U.S. Pat. No. 3,389,965 to Shell discloses a process for producing H.sub.2 by steam reforming of hydrocarbon petroleum fractions over a Re-containing catalyst at 400.degree. to 600.degree. C. or higher, which, of course, results in the formation of CO.sub.2 and CO in very large amounts. The patent, however, does not relate to the selective, partial oxidation of olefins or alcohols or to the production of ketones and other oxygenated products.
Manganese, another Group VIIB metal, has been investigated in various catalyst systems as a catalyst promoter. L. Zanderighi, et al., La Chimica E L'Industria, vol. 56, n. 12, 815-820 (Dec., 1964) report, for a series of propylene-oxidations to a product mixture of acrolein, acetone, acetaldehyde, propylene oxide and methanol, using various tungstates (WO.sub.4.sup.-), of a series of cations, that the reactivities of the tested cations was: Cu&gt;&gt;Bi&gt;Pb&gt;Fe&gt;Tl&gt;Mn. Y. Moro Oka, et al., J. Catalysis, vol. 23, 183-192 (1971) indicates that no oxygenated products other than carbon oxides were found in propylene oxidation over a Mn.sub.2 O.sub.3 --MoO.sub.3 catalyst.
W. H. Davenport et al., "Advances in Rhenium Catalysis", Ind. & Eng. Chem., vol. 60, no. 11, pp. 10-19 (Nov. 1968) states that the chemical and catalytic properties of Re differ considerably from Mn. For example, whereas metallic Mn is highly reactive, slowly decomposes water and reacts with dilute acids, Re metal is relatively inert and does not react with water or nonoxidizing acids. Re catalysts are said to be highly selective hydrogenation catalysts. In the presence of H.sub.2, supported or unsupported Re metal preferentially catalyzes the attack by H.sub.2 upon carbonyl functions over olefinic bonds, while Re oxides catalyze the saturation of C.dbd.C bonds first.
Re-containing hydrogenation catalysts are also disclosed in British Pat. No. 407,127 (1934); H. S. Broadbent et al., J.A.C.S., vol. 76, pp. 1519-1523 (1954); H. S. Broadbent et al., "J. Org. Chem., Volume 24, pp. 1847-1854 (1959) H. S. Broadbent et al., J.A.C.S., vol. 81, pp. 3587-3589 (1959); H. S. Broadbent et al., J. Org. Chem., vol. 27, pp. 4400-4404 (1962).
R. H. Blom et al., Hydrocarbon Proc. & Petr. Refine, vol. 43, no. 10, pp. 132-134 (Oct. 1963) and R. H. Blom et al., Ind. & Eng. Chem., vol. 54, no. 4, pp. 16-22 (April 1962) discuss the use of certain Re catalysts in the dehydrogenation of alcohols to aldehydes and ketones.
Rhenium dehydrogenation catalysts are prepared in U.S.S.R. Pat. No. 52,780 (1938), as abstracted at 34 Chem. Abs. 5467-7; and U.S.S.R. Pat. No. 114,924 (1958), as abstracted at 53 Chem. Abs. 10596f.
Belgian Pat. No. 641,143 (1963) added Re to a supported catalyst containing Fe--Sb oxide on silica to catalyze the oxidation of propylene to acrolein.
British Pat. No. 1,038,262 (1966) employed Re oxides to promote supported and unsupported Co and Ni molybdates and Cu phosphate to oxidize propylene to acrolein or acrylic acid.
British Pat. No. 1,054,864 (1967) obtained significant disproportion of 1-butene (62% butene conversion) over 23% Re.sub.2 O.sub.7 on Al.sub.2 O.sub.3 (at 150.degree. C., atm. pressure) and a space velocity of 1600, to a 62% butene conversion chiefly to propylene and pentene, with some by-product C.sub.2 and C.sub.6 olefins. Olefin methathesis reactions using O.sub.2 and Re oxide/alumina catalysts are discussed in R. Nakamura, et al., J. Molec. Catalysis, vol. 15, pp. 147-156 (1982) (which is not admitted herein to be prior art to our invention).